<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box1 {
            width: 0;
            height: 0;
            /* 1 四个三角做法 */
         /* border-top: 50px solid red;
         border-right: 50px solid blue;
         border-bottom: 50px solid pink;
         border-left: 50px solid purple; */
         /* 2 实现一个三角就是把其他三个边变成透明的 宽高要为0然后如下： */
           /* border: 10px solid transparent;
           border-left-color: skyblue; */
        /* 3 等腰三角做法 宽高为0  */
        /* 四边颜色除了要用的三角有颜色其他都设置透明 */
        border-color: transparent skyblue transparent transparent;
        /* 四条边都是实线 */
        border-style: solid;
        /* 四条边的宽度除了上右都设置为0 （右的取值随父元素的高度，右的取值随比父元素稍小） */
        border-width: 24px 10px 0 0 ;
           
        }
         
        .box2 {
            text-align: center;
            width: 160px;
            height: 24px;
            border: 1px solid red;
            line-height: 24px;
            background-color: #fff;
            margin: 100px auto;
        }

        .box2 .miaosha {
            position: relative;
            float: left;
            width: 90px;
            height: 24px;
            background-color: red;
            font-size: 16px;
            font-weight: 700;
            color: #fff;

        }

        .miaosha i {
            position: absolute;
            top: 0;
            right: 0;
            width: 0;
            height: 0;
            border-color: transparent #fff transparent transparent;
            border-style: solid;
            border-width: 24px 10px 0 0;
        }

        .box2 .yuanjia {
            font-size: 13px;
            color: #666;
            text-decoration: line-through;

        }
    </style>
</head>

<body>
    <div class="box1"></div>
    <div class="box2">
        <span class="miaosha">¥1000.00
            <i></i>
        </span>

        <span class="yuanjia">¥9000.00</span>
    </div>

</body>

</html>